1. Field of the Invention
The present invention relates in general to transducers and more particularly to a transducer with orthogonal lever arm translated motion driven by electromechanical cantilever benders mounted on an inertial tail mass, providing a wideband low frequency response from a low profile apparatus.
2. Background and Discussion
Low frequency underwater sound transducers generally require large housings to provide room for a large compliant active spring needed for both low frequency resonance and high displacement. Lever arm orthogonal action may be used to reduce the height of the enclosure and provide amplified motion. A number of piezoelectric systems have been devised to provide the drive for the lever systems, but these drive systems are generally stiff and usually take the form of extensional drivers such as bars, discs or rings. U.S. Pat. No. 6,654,316 B1 (Nov. 24, 2003) to Butler et al. describes an alternative, more compliant means which uses a piezoelectric bending beam driver to excite the lever arm from the bending displacement at the two ends of the piezoelectric bending beam wherein the beam also acts as an inertial tail mass. U.S. Pat. No. 6,720,708 B2 (Apr. 13, 2004) to Athanas describes an audio loudspeaker in which a transparent curved diaphragm is fixed at one end (or at the center) and driven at the other end (or at the ends) by one or more actuators. However, none of the existing transducers provide an improved operation, particularly a low-frequency, wide-band, low-profile acoustic transducer with lowered resonance under full array loading conditions
Accordingly, it is an object of the present invention to improve the type of motion of the radiating surface of a transducer and to also create a low-frequency, wide-band, low-profile acoustic transducer with lowered resonance under full array loading conditions.
An additional object of the present invention is to provide an improved transducer in which a piston radiator may be added at the location of maximum motion on the lever arm allowing full array loading.
A further object of the present invention is to provide an improved transducer wherein there is obtained a fixed velocity condition in the vicinity of resonance.